ABSTRACT

Freshwater resources are severely declining due to climate change. However, the use of water saving strategies is a prime objective of this century. Many techniques have been developed to cope this core issue. Among them, Partial rhizosphere drying (PRD) being one of the effective approaches plays a major role to reduce the harmful effects of water deficit stress. In PRD, the rhizosphere is divided in two equal halves, each portion irrigated in alternate scheduling to save 50% water. This study was designed to evaluate the performance of five cotton varieties (FH-142, IUB-222, IUB-13, MM-58 and NOOR) under full irrigation (FI) and drought (partial root zone drying, PRD). Results revealed that MM-58 performed the best among other varieties, particularly through improved rate of stomata conductance (32.17%), photosynthesis (24.24%), water-related parameters (16.69%, 36.88% and 43.34% for LRWC, LOP and LTP respectively) and antioxidants activity (19.86%, 43.90%, 20.51% and 21.11% for SOD, POD, CAT and APX respectively) compared to NOOR. Moreover, higher values of growth (PH, LAI) and water related parameters were found in FI while osmolyte accumulation (Sugar and Proline) and antioxidants (SOD, POD, CAT, APX) were more in PRD. In crux, the above traits are the best indicators to screen out any crop varieties especially cotton at the early developmental stage to save time in breeding programs.

摘要

由于气候变化，淡水资源正在严重减少。然而，使用节水策略是本世纪的主要目标。已经开发了许多技术来解决这个核心问题。其中，部分根际干燥（PRD）是一种有效的方法，在减少水分亏缺胁迫的有害影响方面发挥着重要作用。在珠三角，根际被分成相等的两半，每部分交替灌溉，以节省 50% 的水。本研究旨在评估五个棉花品种（FH-142、IUB-222、IUB-13、MM-58 和 NOOR）在完全灌溉（FI）和干旱（部分根区干燥，PRD）下的表现。结果表明，MM-58 在其他品种中表现最好，特别是通过提高气孔导度（32.17%）、光合作用（24.24%）、与 NOOR 相比，与水相关的参数（LRWC、LOP 和 LTP 分别为 16.69%、36.88% 和 43.34%）和抗氧化剂活性（SOD、POD、CAT 和 APX 分别为 19.86%、43.90%、20.51% 和 21.11%）。此外，在 FI 中发现了更高的生长值（PH、LAI）和与水相关的参数，而在 PRD 中，渗透质积累（糖和脯氨酸）和抗氧化剂（SOD、POD、CAT、APX）更多。关键是，上述性状是在早期发育阶段筛选任何作物品种尤其是棉花的最佳指标，以节省育种计划的时间。在 FI 中发现了 LAI) 和水相关参数，而在 PRD 中发现了渗透质积累（糖和脯氨酸）和抗氧化剂（SOD、POD、CAT、APX）更多。关键是，上述性状是在早期发育阶段筛选任何作物品种尤其是棉花的最佳指标，以节省育种计划的时间。在 FI 中发现了 LAI) 和水相关参数，而在 PRD 中发现了渗透质积累（糖和脯氨酸）和抗氧化剂（SOD、POD、CAT、APX）更多。关键是，上述性状是在早期发育阶段筛选任何作物品种尤其是棉花的最佳指标，以节省育种计划的时间。